Float issues...

[Detman101]

When cleaning my carbs of all the rust sediment from the crappy metal filter I had on the bike this lunchbreak....i noticed something.

When I put the carbs with pods back on the bike and hooked everything up. I turned on my pingle valve to let the bowls fill up.
After they had filled, I intentionally left the valve on and cylinders 1&2 started overflowing out the intake side of the carbs thru the pods. I quickly turned the valve off and tried it again. It did it again.

But I noticed that 3&4 did not overflow!!
8O

So this means that the float levels for 1&2 are incorrect yes?
Because if they were correct...the fuel would have stopped at a level low enough to not overflow out of the carbs just like with 3&4 right?

Or does this mean the the float levels for 3&4 are too low and they too should be overflowing when this test is performed?

So confusing...
Dm of mD

 

[Anonymous]

I would say that the float valves aren't built for constant pressure but should (theoretically) hold the level even in prime. Best way is to have the bike running on its center stand with the petcock in the "on" position. Connect a fitting to the bottom of the of the bowl with a transparent tube. You can put the tube up next to the carbs and see where the level is. Think the size is the same as the sync ports, but know adapters that usually come with sync gauges will fit. Obviously, the level anywhere near the top of the float valve won't over flow into the air filter.
Just reread your note. You must be on the side stand. I would think you could be close to the correct setting and still have cylinders 1&2 leak. They must be on the high side though, can't see how bad the overflow is from here. :?

 

[Detman101]

no no no!!! I thought that too but I put the bike on the centerstand when I work on it!

It was on the centerstand and the floats did that!

8O
Dm of mD

 

[Hoomgar]

You have to balance the floats bro if you rebuilt those carbs.
It can be quite a job first time until you get the hang of it.

It is done by simply bending the little center tab (has a name I forget)
to get it right. It sounds crude but that is how it is done. I was looking
for some web sites I know of that describe the procedure but I have those
links at home and can't seem to find them for you. It should be covered
in a good service manual like a Clymer or a factory one.

 

[Detman101]

Then its a factory one cause clymer doesn't say jack about setting floats or even what the stock float height is.

Do you think it would run okay if I put the floats from my spare stock carbs into the stage-3 carbs?

I have no idea what the float height for this bike should be or what the stock setting is.

:?
Dm of mD

 

[robinjo]

Your float height also changes the mixture to some degree.

I am sure someone has a manual with the correct setting for the float height. Make sure you get the height of BOTH sides correct, they can be bent and not linear to each other. Put the carbs up side down and measure from the highest part of the floats down to the ridge the bowl gasket normally rests on.

Float height for my bike with the same 34mm carbs is 22,4mm + or - 1mm, not sure if that is correct for your bike though.

Also check that there is no leaking between the housing of the float needle and the carb, there is an o-ring between then that can go bad. While you have the carbs upside down blow in the fuel pipe, you should hear NO hissing, if you do hear it you can easily identify which carb it is, make sure they're tight, mine were a bit loose once, giving troubles.

 

[Anonymous]

Sorry, somehow had assumed you had set float heights. Don't have a Clymers with me but know they don't explain a lot of things very well, or at all. My own opinion is, I don't see how they pass themselves off as a service manual and charge money for their manual thing. But I know people who think they are great. The factory manual will explain how to tip the carbs upside down and where the height of the floats should be. (with pictures) They also explain the active method I explained earlier with a fitting in the bottom of the fuel bowl, and again explain it with pictures.
Yes, that is the only way to adjust the float height, bending the little metal tabs that rest against the float valve. If that bike is leaking fuel on the center stand I really don't see how it would run for long, it would just flood and shut down. If you have had the carbs out working on them and rested them on the floats, it would bend the tabs so that the float height would be higher. I don't have a manual with me but I'm sure the fuel level shouldn't be above the top of the fuel bowl ( the surface of the bowl where it bolts to the body). I think it is 3mm lower than that. So you can see if fuel is leaking you are way above the specified height.
Your fuel level is most important with it sitting on the center stand running with the petcock on (in its vacuum operating mode). What it does in prime isn't that critical because you hardly ever have it there "but I don't think a correctly adjusted float will overflow like that in prime".
Was this bike running? Make sure the petcock isn't passing fuel in the on position with the engine off, if it is you are really in prime all the time. I don't bother trying to rebuild petcocks anymore, they aren't that much from ronayres.com, just have to wait a couple weeks.
Hope I haven't confused you, you can probably tell I'm an experimenter and nothing even remotely close to a teacher. :?

 

[earlfor]

The correct float height setting for your bike is between 21.4mm and 23.4mm. Set them to 22mm. Or, that would be just a hair line less than 7/8ths inch. Do you know exactly what that measurement is a measurement between? The float tangs/height adjustment is mad by lightly bending the tab/tang that rests on the float needle valve.

Earl

 

[Detman101]

Your float height also changes the mixture to some degree.

I am sure someone has a manual with the correct setting for the float height. Make sure you get the height of BOTH sides correct, they can be bent and not linear to each other. Put the carbs up side down and measure from the highest part of the floats down to the ridge the bowl gasket normally rests on.

Float height for my bike with the same 34mm carbs is 22,4mm + or - 1mm, not sure if that is correct for your bike though.

Also check that there is no leaking between the housing of the float needle and the carb, there is an o-ring between then that can go bad. While you have the carbs upside down blow in the fuel pipe, you should hear NO hissing, if you do hear it you can easily identify which carb it is, make sure they're tight, mine were a bit loose once, giving troubles.

I've replaced the o-rings with the kit that Robert Barr from here sells.
There is no hissing when I did the test you instructed.

I think that my problem is that I do not know which part to measure the float at. That's the reason I wanted to put the stock carbs floats in these modded carbs...hoping that the level was already set on the stock floats.

Dm of mD

 

[Detman101]

Sorry, somehow had assumed you had set float heights. Don't have a Clymers with me but know they don't explain a lot of things very well, or at all. My own opinion is, I don't see how they pass themselves off as a service manual and charge money for their manual thing. But I know people who think they are great. The factory manual will explain how to tip the carbs upside down and where the height of the floats should be. (with pictures) They also explain the active method I explained earlier with a fitting in the bottom of the fuel bowl, and again explain it with pictures.
Yes, that is the only way to adjust the float height, bending the little metal tabs that rest against the float valve. If that bike is leaking fuel on the center stand I really don't see how it would run for long, it would just flood and shut down. If you have had the carbs out working on them and rested them on the floats, it would bend the tabs so that the float height would be higher. I don't have a manual with me but I'm sure the fuel level shouldn't be above the top of the fuel bowl ( the surface of the bowl where it bolts to the body). I think it is 3mm lower than that. So you can see if fuel is leaking you are way above the specified height.
Your fuel level is most important with it sitting on the center stand running with the petcock on (in its vacuum operating mode). What it does in prime isn't that critical because you hardly ever have it there "but I don't think a correctly adjusted float will overflow like that in prime".
Was this bike running? Make sure the petcock isn't passing fuel in the on position with the engine off, if it is you are really in prime all the time. I don't bother trying to rebuild petcocks anymore, they aren't that much from ronayres.com, just have to wait a couple weeks.
Hope I haven't confused you, you can probably tell I'm an experimenter and nothing even remotely close to a teacher. :?

Well, I guess beased on what you have stated that I need to lower the fuel level in bowls #1&2. I will do that this afternoon and see if those two cylinders are still running super rich. It's funny. When I measure them they all are at the same level. Maybe my ruler is messed up or something.
Damnit. Can't i just buy floats with the height already adjusted or something?


I've got a stock set of identical carbs that haven't been messed with. Could I just put the floats from those in these carbs?

:x
Dm of mD

 

[Hoomgar]

The correct float height setting for your bike is between 21.4mm and 23.4mm. Set them to 22mm. Or, that would be just a hair line less than 7/8ths inch. Do you know exactly what that measurement is a measurement between? The float tangs/height adjustment is mad by lightly bending the tab/tang that rests on the float needle valve.

Earl

That's the word I was groping for

I've got a stock set of identical carbs that haven't been messed with. Could I just put the floats from those in these carbs?

:x
Dm of mD

You will be in the same boat. All carbs are slightly different and require adjustment. Thats why this is an issue in the first place. It's just a matter of getting them all set to the same height. And the correct height.

 

[Detman101]

Crap, hell...I'm letting someone else deal with this.
Time to save up some more money.
This better not cost me another 500 dollars this time.


:evil:
Dm of mD

 

[Anonymous]

Float issues..........

Float issues..........

Haynes do a carburettor manual that'll show you how to sort the float heights and set up carbs.Even I've found it really useful and I can be a total muppet at times.Try it,it'll save you a good bit cash.
http://www.haynes.com/na401.html#anchor1228398.
Scroll down to the Specialty Manuals section.

 

[Detman101]

3514 - Motorcycle fuel Systems Manual (Suggested retail price $26.95)

That one? I'll order it on monday!

Well, I switched the floats with the other carbs and found that they are already set right. The tang looked almost flat when I looked at them but the height was correct. I measured them with my new digital caliper I picked up. Don't ask how much it cost... :roll:

Test drive: Still hosed. The bike reeks of heavy gas at idle and still hesitates and lean-pops when you try to ride it.
Damnit to all hell...I'm never gonna f'n get to ride this damn bike.
I'm gonna lose my sanctification cause of this damn machine.

:evil:

Ah well, screw it. At least the floats are all the same height now.

:x
Dm of mD

 

[Detman101]

Damnit, for once I wish I could just have a damned fried stator or something instead of having a bike that keeps me in carburetor hell.


Dm of mD

 

[Detman101]

Well, it appears that the pods are not my problem. It's the carbs. They are too damn rich...again.

I'm going to reset them to the specs that they were at when they were set up to work with the stock exhaust and see how it does (IE: 122.5 Mikuni mains, 1 turn out on the mix screws)

Dm of mD